Actually, dark paint/anodizing increases the heat transfer from the dark body into the environment when the body is warmer, and also increases the absorption of heat, when the environment is warmer. Studied this at Uni as part of applied electronics, as well as thermodynamics.

Anodizing is a relatively good conductor of heat (albeit not as good as aluminum or any other metal, for that matter), and the very thin layer of anodizing has more of a beneficial efect in transmitting the heat from the heatsinks (or rims) into the environment, rahter than adverse (due to lesser thermal conductivity than metal).

However, this effect is very small, and nowadays manufacturers often don't anodize heat sinks, as it's considered more expensive than just increasing the heatsink surface area by, say, 2%.

You guys also missed the part where he states that heat is generated in the brake pads and not the rim; what kind of double-talk is that?

The heat is generated by the friction between the pads and the rim, and is not excusive to one part or the other.

Most importantly, I think, is the scale of dynamics are not great enough for the insulation factor to really matter.